- compressing-output-port output-port #!key (level 3)procedure
Returns an output-port to which uncompressed data can be written, and its compressed form will be written to output-port. It is important to close this port in order to flush internal zstd buffers. Closing this output-port does not close output-port.
If level is supplied, it sets the compression level as documented by man zstd, and should be an integer in the range [1-19].